Generally a raceway pond is a shallow artificial pond used in growth of microorganisms like algae. The Raceway pond can be of two types open ponds and closed ponds. The raceway ponds have been used for different types of industrial requirements. The raceway pond consists of many rectangular grids connected to and in fluid communication with each other and each rectangular grid consists of one channel in an oval shape to form automotive raceway circuit. Also, each rectangular grid of raceway pond consists of a dividing element that turns the flow of fluid by 180° therewithin. The raceway pond may consists of a pumping mechanism such as paddle wheel in the rectangular grids to induce the flow movement required for various purposes such as waste water treatment, microorganism growth such as bacteria, algae, and for mixing of ingredients such as chemical ingredients.
Typically, the velocity of the fluid in the raceway pond is about 10-40 cm/s and the depth of the fluid in the raceway pond is about 15-30 cm. The bends of the dividing-element forms hairpin like structure or dumbbell like structure. Basically, while the raceway pond is in operation, the fluid flowing takes 180° turn near the bends of each dividing-element and this leads to boundary layer separation at the extremities of the dividing-element leading to the recirculation of fluid and fluid velocity stratification. This, in turn, leads to the formation of dead zones in the immediate vicinity of the bends. The dead zones result in an increase in the population of unwanted microorganisms such as grazers that leads to frequent crashing of the raceway pond, which may be caused due to inefficient mixing. In comparing the energy efficiency of different high rate algal raceway pond designs using computational fluid dynamics, Chemical Engineering Research and Design, 2012, Liffman et al proposes a number of 3-D bend geometric s that deflect the flow to the outer edge of the bend and retain a channel cross-sectional area, thereby minimizing energy losses due to centrifugal forces. Numerical modeling was used to model bend configurations. Some of the new bend designs such as “narrow”, “medium”, “wide” box designs not only minimizes energy consumption but also improves the mixing of the raceway pond by removing low speed and stagnation regions within the flow. Specifically, Liffman et al discloses a cultivation pond with symmetrical tear-drop profile on both sides of the dividing-element of each rectangular grid for improving the fluid flow profile.
However, the symmetrical tear-drop profile on both the sides of the dividing-element reduces the area available for the growth of microorganisms, thereby increasing the pressure drop and hence such system as disclosed by Liffman et al consumes more power.
Further, United States Patent Application US20120272574 discloses algae cultivation ponds having a contraction zone, an expansion zone, and vanes within the expansion zone of the cultivation pond. This patent application discloses the cultivation pond having the bend at any one of the extremity of the dividing-element that forms the tear-drop profile at any one side of the extremity of the dividing-element.
However, from the prior art, it is observed that the way the bend of the dividing-element is configured at the extremities of the dividing-element of the raceway, inevitably leads to one or more disadvantages:
One disadvantage of the conventional system is that it fails to provide a system with minimized dead zones and velocity stratification around the bend regions of the system.
Another disadvantage of the conventional system is that it does not eliminate local recirculation of the fluid flowing within the system and prohibiting for flow separation.
Still another disadvantage of the conventional system is that it does not provide a system with minimal energy losses associated with the fluid flow at the bends within the system.
Yet another disadvantage of the conventional system is that it does not provide a system with minimal power requirement for fluid flow.
Yet another disadvantage of the conventional system is that it does not provide a system with minimal loss of operational area.
Further another disadvantage of the conventional system is that it does not provide a system with improved hydrodynamic behavior.
Hence, in order to obviate the above mentioned problems associated with the conventional system for the growth of microorganisms, it is necessary to re-design the bend configured at one of the extremity of the dividing-element of the raceway pond for improving fluid circulation in a fluid-body.
Objects
Some of the objects of the present disclosure aimed to ameliorate one or more problems of the prior art or to at least provide a useful alternative are listed herein below.
It is an object of the present disclosure to eliminate drawbacks associated with conventional system for improving fluid circulation in a fluid-body that fail to provide a system with minimized dead zones and velocity stratification around the bend regions of the system.
Another object of the present disclosure is to provide a system which eliminates local recirculation of the fluid flowing within the system and prohibiting for flow separation.
Yet another object of the present disclosure is to provide a system with minimal energy losses associated with the fluid flow at the bends within the system.
Still another object of the present disclosure is to provide a system with minimal power requirement for fluid flow.
Further object of the present disclosure is to provide a system with minimal loss of operational area.
Yet another object of the present disclosure is to provide a system with improved hydrodynamic behavior.
The other objects and advantages of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures, which are not intended to limit the scope of the present disclosure.